WATER SOILS. 1061 



other hand, the minimum temperatures were lower on plowed soil than on unplowed 

 by almost 1 degree. — p. fireman. 



The maintenance of fertility. Liming the soil, 0. E. Thorne ( Ohio Sta. Bui. 

 159, pp. 165-196, tigs. 12). — The bulletin discusses the functions of lime in the soil, 

 -the average amounts of lime, potash, nitrogen, and phosphoric acid found in average 

 crops of corn, oats, wheat, clover, and timothy as grown in Ohio, and describes 

 methods of determining the need of lime in soils, the kinds of lime to use, and the 

 best methods of application. It summarizes results of field experiments recently 

 undertaken on the cold, heavy clay soil of the test farm at Strongsville and the worn 

 clay soil of the test farm at Germantown, as well as results of experiments which 

 have been carried on for a series of years on the light sandy clay soil of the station farm 

 at Wooster with corn, clover, oats, and wheat. 



The soil at the main station "has been under exhaustive cropping for many years, 

 and though requiring liberal manuring or fertilizing for the production of profitable 

 crops, it responds promptly to such treatment." It has been increasingly difficult 

 to grow clover on this soil during recent years. The growth of clover has also been 

 poor on the soil of the test farm at Strongsville, but somewhat better on that at Ger- 

 mantown, though not entirely satisfactory. 



"On the soil of the main station, naturally somewhat deficient in lime because of 

 its origin, the condition unfavorable to clover is aggravated by the use of fertilizing 

 materials originally compounded with acid, such as acid phosphate, potassium 

 chlorid, and ammonium sulphate, although these materials are by no means the sole 

 cause of this condition. On this soil a luxuriant growth of clover has been secured 

 by the use of lime, in conjunction with materials carrying both phosphorus and 

 potassium. Lime alone, though increasing the growth of clover somewhat, does not 

 produce a full yield nor does such a yield follow the use of lime in association with 

 a carrier of phosphorus only or of potassium only. When the lime has been applied 

 to the corn crop, 2 years before the clover seed was sown, the corn being followed by 

 oats and wheat, the effect on the clover has been much better than when the lime was 

 applied to the wheat crop the fall before sowing the clover seed. . . . 



"When lime has been applied directly to the wheat crop it has sometimes reduced 

 the yield of wheat. When an increase of wheat has immediately followed liming 

 the gain seems to have been largely due to the opening up of a refractory clay soil 

 by the lime. 



"A ton of lime to the acre has been sufficient to produce a luxuriant growth of 

 clover at the main station, together with a considerable increase in the cereal crops 

 preceding the clover. It is possible that a smaller quantity would have sufficed. 

 On this point investigations are in progress. At the Strongsville test farm, however, 

 the present indications are that a much larger quantity of lime may be required. 



"Thus far the effect of lime at the Germantown test farm has been negative, if 

 not actually injurious. 



"No superiority has yet been discovered in 'hydrated' lime over ordinary lime." 



On the lime requirements of plants, O. Loew (Landw. Jahrb., 34 (1905), No. 1, 

 pp. 131-137). — Replying to criticisms by Meyer, of the author's well-known hypothe- 

 sis, the latter summarizes the results of various investigations to confirm his conclu- 

 sion that, other things being equal, plants thrive best when there is a certain definite 

 relation between lime and magnesia in the medium in which they grow. 



Factors in crop production with special reference to permanent agriculture 

 in Illinois, 0. G. Hopkins (Illinois Sta. Circ. 87, pp. 32). —This is a paper which 

 was read before the Illinois State farmers' institute at Joliet in February, 1905. 



It emphasizes the importance of producing and maintaining large crop yields on 

 Illinois lands, and illustrates in some detail the principle of measuring land values 

 by crop yields, on the basis of selling the crops at the local markets. The discussion 

 is confined largely to the subject of plant food, but reference is also made to 5 other 



